Solid dielectric capacitor and method of manufacture

ABSTRACT

A monolithic capacitor having a dielectric ceramic body cosintered with at least two base metal electrodes. The ceramic body is composed of a major ingredient expressed by the formula, 
     
         (1-α){(Ba.sub.k-x-z M.sub.x L.sub.z)O.sub.k (Ti.sub.1-y 
    
      R y )O 2- (y/2) }+αCaZrO 3   
     where M is either or both of magnesium and zinc, L is either or both of calcium and magnesium, R is a rare earth element or elements, and α, k, x, z and y are numerals in specified ranges. To this major ingredient is added a minor proportion of an additive ingredient. The additive ingredient is a mixture of boric oxide or lithium oxide, silicon dioxide and at least one metal oxide selected from among barium oxide, strontium oxide, calcium oxide, magnesium oxide and zinc oxide. For the fabrication of capacitors the mixture of the above major ingredient and additives in finely divided form are formed into moldings of desired shape and size, each with at least two electrodes buried therein. The moldings and electrodes are cosintered in a reductive or neutral atmosphere at temperatures of less than 1200 degrees C. and then are heated at a lower temperature in an oxidative atmosphere.

BACKGROUND OF THE INVENTION

Our invention relates to solid dielectric capacitors and moreparticularly to a monolithic ceramic capacitor comprising a single ormultiple layered ceramic body and at least two electrodes in contacttherewith. The invention also pertains to a method of fabrication suchcapacitors.

Multilayered ceramic capacitors have long been known and usedextensively which employ noble metals such as platinum and palladium asthe electrode materials. Generally, for the fabrication of suchcapacitors, "green" (unsintered) dielectric sheets have first beenprepared from the proportioned ingredients of a desired dielectricceramic material in finely divided form. An electroconductive pastecontaining powdered platinum or palladium has then been "printed" on thegreen sheets in a desired pattern. Then a plurality of such printedgreen sheets have been stacked up, pressed together, and sintered in atemperature range of 1300 degrees to 1600 degrees C. in an oxidativeatmosphere.

This conventional method makes possible the simultaneous firing(cosintering) of the dielectric ceramic layers and the film electrodesinterleaved therewith. It is also an acknowledged advantage of thisknown method that the noble metal electrodes are totally unaffected bythe high temperature sintering in an oxidative atmosphere. Offsettingall such advantages is the expensiveness of the noble metals, which addsubstantially to the manufacturing costs of the multilayered ceramiccapacitors.

Wada et al. U.S. Pat. No. 4,610,969, assigned to the assignee of theinstant application, suggests a solution to the above problem. Itteaches dielectric ceramic compositions consisting of a major ingredientexpressed by the formula, (Ba_(k-x) M_(x))O_(k) TiO₂, where M is atleast either of magnesium (Mg) and zinc (Zn), and additives consistingof lithium oxide (Li₂ O) and silicon dioxide (SiO₂). The compositionsmay, or may not, additionally include at least one metal oxide selectedfrom among barium oxide (BaO), calcium oxide (CaO) and strontium oxide(SrO).

Another solution is found in Wada et al. U.S. Pat. No. 4,610,970, whichproposes ceramic compositions whose major ingredient is expressed by theformula, (Ba_(k-x-y) M_(x) L_(y))O_(k) TiO₂, where M is at least eitherof Mg and Zn, and L is at least either of Sr and Ca. To this majoringredient are added Li₂ O, SiO₂ and, optionally, at least one othermetal oxide selected from among BaO, CaO and SrO.

Wada et al. U.S. Pat. No. 4,610,971 suggests still another solution,teaching use of a major ingredient expressed by the formula, (Ba_(k-x)M_(x))O_(x) TiO₂, where M is at least one of Mg, Zn, Sr and Ca. Thismajor ingredient is admixed with boric oxide (B₂ O₃), SiO₂ and,optionally, at least one other metal oxide selected from among BaO, MgO,ZnO, Sro and CaO.

A further solution is found in Wada et al. U.S. Pat. No. 4,610,968,which proposes ceramic compositions including a major ingredientexpressed by the formula, (Ba_(k-x) M_(x))O_(x) TiO₂, where M is atleast one of Mg, Zn, Sr and Ca. This major ingredient is admixed with B₂O₃ and at least one metal oxide selected from among BaO, MgO, ZnO, SrOand CaO.

All the foregoing known compositions make possible the fabrication ofceramic bodies by firing at temperatures of not more than 1200 degreesC. in a nonoxidative (reductive or neutral) atmosphere. The ceramicbodies may therefore be cosintered with electrodes of a base metal suchas nickel. The resulting capacitors have specific dielectric constantsof not less than 2000, and the temperature dependences of theircapacitances are within plus or minus 10 percent in a temperature rangeof -25 degrees to +85 degrees C.

While these values are satisfactory for all practical purposes, we havenevertheless been hard pressed by our customers, with the recentdevelopment of microelectronics, for ceramic capacitors that have higherspecific dielectric constants with no less temperature dependences.

SUMMARY OF THE INVENTION

We have hereby invented how to manufacture ceramic capacitors that havehigher dielectric constants, with less temperature dependences over awide temperature range, than heretofore and which can be formed byfiring in a temperature range of not more than 1200 degrees C. in anonoxidative atmosphere.

Briefly stated in one aspect thereof, our invention provides a soliddielectric capacitor of the above improved characteristics, comprising alow temperature sintered dielectric ceramic body and at least twoelectrodes in contact therewith. The ceramic body consists essentiallyof 100 parts by weight of a major ingredient that is expressed by theformula, (1-α){(Ba_(k-x-z) M_(x) L_(z))O_(k) (Ti_(1-y) R_(y))O₂₋(y/2)}αCaZrO₃, and 0.2 to 5.0 parts by weight of an additive mixture(hereinafter referred to as the additive ingredient) of at least twomembers selected from the group consisting of B₂ O₃ or Li₂ O, SiO₂ andat least one of BaO, SrO, CaO, MgO and ZnO. In the formula of the majoringredient, M is either or both of magnesium and zinc, L is either orboth of calcium and strontium, R is at least one metal selected fromscandium(Sc), yttrium(Y), gadolinium(Gd), dysprosium(Dy), holmium(Ho),erbium(Er), ytterbium(Yb), terbium(Tb), thulium(Tm) and lutetium(Lu), αis a numeral in the range of 0.005 to 0.040 , k is a numeral not lessthan 1.00 and not more than 1.05, x is a numeral greater then 0 and lessthan 0.10, z is a numeral greater than 0 and not greater than 0.05, thesum of x and z is a numeral not less than 0.01 and not greater than 0.1,and y is a numeral greater than 0 and not greater than 0.04. Therelative proportions of B₂ O₃ or Li₂ O, SiO₂ and at least one selectedmetal oxide, altogether constituting the additive mixture, will bespecified with reference to the ternary diagrams attached hereto.

Another aspect of our invention concerns a method of fabricating theceramic capacitor having the ceramic body of the above specifiedcomposition. The method dictates, first of all, the preparation of amixture of the above specified major ingredient and additives in finelydivided form. This mixture is then molded into a body of desired shapeand size, which is provided with at least two electrode portions of anelectroconductive material in any convenient manner. Then the moldingswith the electrode portions are cosintered in a reductive or neutralatmosphere and is subsequently heated in an oxidative atmosphere.

The dielectric ceramic composition of our invention, set forth in theforegoing, makes it possible to sinter the moldings in a nonoxidativeatmosphere at temperatures not exceeding 1200 degrees C. A preferredtemperature range for this molding operation is from 1050 degrees to1200 degrees C. The sintering temperatures of less than 1200 degrees C.enable the use of nickel or like low cost base metal as the electrodematerial in cosintering the ceramic boy and the electrodes.

Therefore, in the fabrication of ceramic capacitors by the method of ourinvention, an electroconductive paste of powdered nickel or like basemetal may be printed, coated, or otherwise formed on green sheets of thedielectric ceramic compositions in accordance with our invention. Thegreen sheets and the electroconductive layers thereon may be cosinteredat temperatures of not more than 1200 degrees C.

The ceramic capacitors of our invention have proved to have veryfavorable physical and performance characteristics. The test capacitorsmanufactured in accordance with our invention, to be disclosedsubsequently, had specific dielectric constants of more than 3000,dielectric losses of not more than 2.5%, and resistivities of not lessthan 1×10⁶ megohm-centimeters. Also the temperature dependences of theirspecific dielectric constants were from -15% to +15% of the value at 25degrees C. in a temperature range of -55 degrees to +125 degrees C., andfrom -10% to +10% of the value at 20 degrees C. in a temperature rangeof -25 degrees to +85 degrees C.

The above and other features and advantages of our invention and themanner of realizing them will become more apparent, and the inventionitself will best be understood, from a study of the followingdescription and appended claims taken together with the attacheddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section through a monolithic, multilayered ceramic capacitorcapable of fabrication in accordance with the teaching of our invention,the illustrated capacitor being representative of numerous testcapacitors manufactured in the Examples of our invention to be presentedsubsequently;

FIG. 2 is a ternary diagram depicting the relative proportions of thesecond additives of the ceramic compositions in accordance with Examples1-139 of our invention; and

FIG. 3 is a ternary diagram depicting the relative proportions of thesecond additives of the ceramic compositions in accordance with Examples140-170 of our invention.

DETAILED DESCRIPTION

We have illustrated in FIG. 1 one of many monolithic ceramic capacitorsof like construction fabricated in the subsequent Examples of ourinvention by way of a preferable embodiment thereof. Generallydesignated 10, the representative capacitor is shown to have aninterlamination of three dielectric ceramic layers 12 and two filmelectrodes 14. The three ceramic layers 12 constitute in combination asolid dielectric body 15 having the low temperature sinterable ceramiccompositions in accordance with our invention. The two film electrodes14, which can be of a low cost base metal such as nickel, extend fromboth sides of the dielectric body 15 toward, and terminate short of, theopposite sides of the dielectric body and so have an overlapping,parallel spaced relation to each other.

The capacitor 10 also includes a pair of conductive terminations 16which are formed on both sides of the dielectric body 15 and whichcontact the respective film electrodes 14. Each termination 16 is shownto comprise a baked on zinc layer 18, a plated on copper layer 20, and aplated on solder layer 22.

Typically, and as fabricated in the subsequent Examples of ourinvention, the intermediate one of the three dielectric layers 12 has athickness of 0.02 millimeter (mm). The area of that part of each filmelectrode 14 which overlaps the other film electrode is 25 mm² (5×5 mm).

EXAMPLES

We fabricated 170 different sets of test capacitors, each constructed asshown in FIG. 1, some having their dielectric bodies formulated inaccordance with the ceramic compositions of our invention and othersnot. Then we measured the specific dielectric constant, dielectric loss,resistivity, and temperature dependence of capacitance of the testcapacitors. Tables 1, 2 and 3 list the compositions of the dielectricbodies of all the test capacitors fabricated.

We have previously defined the major ingredient of the ceramiccompositions in accordance with our invention by the general formula,

    (1-α){(Ba.sub.k-x-z M.sub.x L.sub.z)O.sub.k (Ti.sub.1-y R.sub.y)O.sub.2-(y/2) }+αCaZrO.sub.3.

Thus, in Table 1, we have given various combinations of (1-α), α,(k-x-z), x, z and (x+z) in the formula to indicate the specific majoringredients employed in the various Tests. The (1-α) and α indicate therelative proportions of {(Ba_(k-x-z) M_(x) L_(z))O_(k) (Ti_(1-y)R_(y))O₂₋(y/2) } and CaZrO₃ of the major ingredient in moles. The(k-x-z), x and z indicate the atomicities of the associated elements.Since M can be either or both of Mg and Zn, the column under X issubdivided into the atomicities of these elements and their sum (X).Also, since L can be either or both of Ca and Sr, the column under z islikewise subdivided into the atomicities of these elements and their sum(z). The (x+z) is the sum of x and z.

In Table 2, we have given various combinations of y and k in the formulato indicate the specific majior ingredients employed in the variousTests. Since R is at least one metal selected from Sc, Y, Gd, Dy, Ho, Erand Yb, the column under y is subdivided into the atomicities of theseelements and their sum(y). The k indicates the atmicity of the element(O).

The ceramic compositions of our invention furthermore include anadditive ingredient or glass ingredient. The additive ingredient is aadditive mixture of B₂ O₃, SiO₂ and MO or a additive mixture of Li₂ O,SiO₂ and MO. Table 3 specifies the proportions, in parts by weight, ofthe additive ingredient with respect to 100 parts by weight of the majoringredient. Also, Table 3 specifies the relative proportions, in molepercent, of the additive ingredients B₂ O₃, Li₂ O, SiO₂, and MO.Further, since MO can be any one or more of BaO, MgO, ZnO, SrO and CaO,Table 3 gives the relative proportions, in mole percent, of these metaloxides. In the Table 3, the additives of Tests Nos. 1-139 consist of Li₂O, SiO₂ and MO, and the additive of Tests Nos. 140-170 consist of B₂ O₃,SiO₂ and MO.

                                      TABLE 1                                     __________________________________________________________________________    Ceramic Compositions                                                          Major Ingredient (100 wt. parts)                                              Test           X        Z                                                     No.                                                                              1-α                                                                        α                                                                          k - x - z                                                                           Mg Zn Sum                                                                              Ca Sr Sum                                                                              x + z                                        __________________________________________________________________________     1 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                          2 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                          3 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                          4 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                          5 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                          6 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                          7 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                          8 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                          9 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         10 0.98                                                                             0.02                                                                             0.96  0.95                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         11 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         12 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         13 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         14 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         15 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         16 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         17 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         18 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         19 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         20 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         21 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         22 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         23 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         24 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         25 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         26 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         27 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         28 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         29 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         30 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         31 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         32 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         33 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         34 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         35 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         36 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         37 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         38 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         39 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         40 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         41 0.98                                                                             0.02                                                                             0.96  0.05                                                                             0  0.05                                                                             0  0.01                                                                             0.01                                                                             0.06                                         42 0.98                                                                             0.02                                                                             0.96  0.01                                                                             0.01                                                                             0.02                                                                             0.04                                                                             0  0.04                                                                             0.06                                         43 0.98                                                                             0.02                                                                             0.97  0  0.01                                                                             0.01                                                                             0.04                                                                             0  0.04                                                                             0.05                                         44 0.98                                                                             0.02                                                                             0.97  0  0.01                                                                             0.01                                                                             0.04                                                                             0  0.04                                                                             0.05                                         45 0.98                                                                             0.02                                                                             0.97  0  0.01                                                                             0.01                                                                             0.04                                                                             0  0.04                                                                             0.05                                         46 0.98                                                                             0.02                                                                             0.97  0  0.01                                                                             0.01                                                                             0.04                                                                             0  0.04                                                                             0.05                                         47 0.98                                                                             0.02                                                                             0.97  0  0.01                                                                             0.01                                                                             0.04                                                                             0  0.04                                                                             0.05                                         48 0.995                                                                            0.005                                                                            0.96  0.06                                                                             0  0.06                                                                             0.02                                                                             0  0.02                                                                             0.08                                         49 0.995                                                                            0.005                                                                            0.96  0.06                                                                             0  0.06                                                                             0.02                                                                             0  0.02                                                                             0.08                                         50 0.995                                                                            0.005                                                                            0.96  0.06                                                                             0  0.06                                                                             0.02                                                                             0  0.02                                                                             0.08                                         51 0.995                                                                            0.005                                                                            0.96  0.06                                                                             0  0.06                                                                             0.02                                                                             0  0.02                                                                             0.08                                         52 0.995                                                                            0.005                                                                            0.96  0.06                                                                             0  0.06                                                                             0.02                                                                             0  0.02                                                                             0.08                                         53 0.995                                                                            0.005                                                                            0.96  0.06                                                                             0  0.06                                                                             0.02                                                                             0  0.02                                                                             0.08                                         54 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         55 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         56 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         57 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         58 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         59 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         60 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         61 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         62 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         63 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         64 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         65 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         66 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         67 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         68 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         69 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         70 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         71 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         72 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         73 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         74 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         75 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         76 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         77 0.96                                                                             0.04                                                                             0.96  0  0.04                                                                             0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         78 1  0  0.91  0.06                                                                             0  0.06                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.1                                          79 0.995                                                                            0.005                                                                            0.91  0.06                                                                             0  0.06                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.1                                          80 0.98                                                                             0.02                                                                             0.91  0.06                                                                             0  0.06                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.1                                          81 0.96                                                                             0.04                                                                             0.91  0.06                                                                             0  0.06                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.1                                          82 0.95                                                                             0.05                                                                             0.91  0.06                                                                             0  0.06                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.1                                          83 1  0  0.97  0  0.05                                                                             0.05                                                                             0.02                                                                             0  0.02                                                                             0.07                                         84 0.995                                                                            0.005                                                                            0.97  0  0.05                                                                             0.05                                                                             0.02                                                                             0  0.02                                                                             0.07                                         85 0.98                                                                             0.02                                                                             0.97  0  0.05                                                                             0.05                                                                             0.02                                                                             0  0.02                                                                             0.07                                         86 0.96                                                                             0.04                                                                             0.97  0  0.05                                                                             0.05                                                                             0.02                                                                             0  0.02                                                                             0.07                                         87 0.95                                                                             0.05                                                                             0.97  0  0.05                                                                             0.05                                                                             0.02                                                                             0  0.02                                                                             0.07                                         88 0.98                                                                             0.02                                                                             1     0  0  0  0  0  0  0                                            89 0.98                                                                             0.02                                                                             0.99  0.005                                                                            0  0.005                                                                            0.005                                                                            0  0.005                                                                            0.01                                         90 0.98                                                                             0.02                                                                             0.99  0.005                                                                            0  0.005                                                                            0  0.005                                                                            0.005                                                                            0.01                                         91 0.98                                                                             0.02                                                                             0.99  0  0.005                                                                            0.005                                                                            0.005                                                                            0  0.005                                                                            0.01                                         92 0.98                                                                             0.02                                                                             0.99  0  0.005                                                                            0.005                                                                            0  0.005                                                                            0.005                                                                            0.01                                         93 0.98                                                                             0.02                                                                             0.94  0.02                                                                             0.02                                                                             0.04                                                                             0.02                                                                             0  0.02                                                                             0.06                                         94 0.98                                                                             0.02                                                                             0.94  0.02                                                                             0.02                                                                             0.04                                                                             0  0.02                                                                             0.02                                                                             0.06                                         95 0.98                                                                             0.02                                                                             0.94  0.02                                                                             0  0.02                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.06                                         96 0.98                                                                             0.02                                                                             0.94  0  0.02                                                                             0.02                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.06                                         97 0.98                                                                             0.02                                                                             0.92  0.02                                                                             0.02                                                                             0.04                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.08                                         98 0.98                                                                             0.02                                                                             0.88  0.03                                                                             0.03                                                                             0.06                                                                             0.03                                                                             0.03                                                                             0.06                                                                             0.12                                         99 0.98                                                                             0.02                                                                             0.97  0.02                                                                             0  0.02                                                                             0  0.01                                                                             0.01                                                                             0.03                                         100                                                                              0.98                                                                             0.02                                                                             0.95  0.01                                                                             0  0.01                                                                             0  0.04                                                                             0.04                                                                             0.05                                         101                                                                              0.98                                                                             0.02                                                                             0.92  0.04                                                                             0  0.04                                                                             0  0.04                                                                             0.04                                                                             0.08                                         102                                                                              0.98                                                                             0.02                                                                             0.9   0.05                                                                             0  0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          103                                                                              0.98                                                                             0.02                                                                             0.9   0  0.1                                                                              0.1                                                                              0  0  0  0.1                                          014                                                                              0.98                                                                             0.02                                                                             0.88  0.06                                                                             0  0.06                                                                             0.06                                                                             0  0.06                                                                             0.12                                         105                                                                              0.98                                                                             0.02                                                                             0.88  0.06                                                                             0.06                                                                             0.12                                                                             0  0  0  0.12                                         106                                                                              0.97                                                                             0.03                                                                             0.94  0  0  0  0.04                                                                             0.02                                                                             0.06                                                                             0.06                                         107                                                                              0.97                                                                             0.03                                                                             0.95  0  0.05                                                                             0.05                                                                             0.05                                                                             0  0.05                                                                             0.1                                          108                                                                              0.97                                                                             0.03                                                                             0.95  0.05                                                                             0  0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          109                                                                              0.97                                                                             0.03                                                                             1     0.02                                                                             0.01                                                                             0.03                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.05                                         110                                                                              0.97                                                                             0.03                                                                             0.97  0.03                                                                             0.01                                                                             0.04                                                                             0.03                                                                             0.01                                                                             0.04                                                                             0.08                                         111                                                                              0.97                                                                             0.03                                                                             0.95  0.03                                                                             0.02                                                                             0.05                                                                             0.03                                                                             0.02                                                                             0.05                                                                             0.1                                          112                                                                              0.97                                                                             0.03                                                                             0.93  0.03                                                                             0.03                                                                             0.06                                                                             0.03                                                                             0.03                                                                             0.06                                                                             0.12                                         113                                                                              0.98                                                                             0.02                                                                             0.94  0.02                                                                             0  0.02                                                                             0.02                                                                             0  0.02                                                                             0.04                                         114                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0  0.02                                                                             0.02                                                                             0  0.02                                                                             0.04                                         115                                                                              0.98                                                                             0.02                                                                             0.99  0.02                                                                             0  0.02                                                                             0.02                                                                             0  0.02                                                                             0.04                                         116                                                                              0.98                                                                             0.02                                                                             1.01  0.02                                                                             0  0.02                                                                             0.02                                                                             0  0.02                                                                             0.04                                         117                                                                              0.98                                                                             0.02                                                                             1.03  0.02                                                                             0  0.02                                                                             0.02                                                                             0  0.02                                                                             0.04                                         118                                                                              0.99                                                                             0.01                                                                             0.9   0.01                                                                             0.03                                                                             0.04                                                                             0.01                                                                             0.03                                                                             0.04                                                                             0.08                                         119                                                                              0.99                                                                             0.01                                                                             0.92  0.01                                                                             0.03                                                                             0.04                                                                             0.01                                                                             0.03                                                                             0.04                                                                             0.08                                         120                                                                              0.99                                                                             0.01                                                                             0.95  0.01                                                                             0.03                                                                             0.04                                                                             0.01                                                                             0.03                                                                             0.04                                                                             0.08                                         121                                                                              0.99                                                                             0.01                                                                             0.97  0.01                                                                             0.03                                                                             0.04                                                                             0.01                                                                             0.03                                                                             0.04                                                                             0.08                                         122                                                                              0.99                                                                             0.01                                                                             0.99  0.01                                                                             0.03                                                                             0.04                                                                             0.01                                                                             0.03                                                                             0.04                                                                             0.08                                         123                                                                              0.98                                                                             0.02                                                                             0.96  0.04                                                                             0  0.04                                                                             0  0.02                                                                             0.02                                                                             0.06                                         124                                                                              0.98                                                                             0.02                                                                             0.96  0.04                                                                             0  0.04                                                                             0  0.02                                                                             0.02                                                                             0.06                                         125                                                                              0.98                                                                             0.02                                                                             0.96  0.04                                                                             0  0.04                                                                             0  0.02                                                                             0.02                                                                             0.06                                         126                                                                              0.98                                                                             0.02                                                                             0.96  0.04                                                                             0  0.04                                                                             0  0.02                                                                             0.02                                                                             0.06                                         127                                                                              0.98                                                                             0.02                                                                             0.96  0.04                                                                             0  0.04                                                                             0  0.02                                                                             0.02                                                                             0.06                                         128                                                                              0.97                                                                             0.03                                                                             0.94  0  0.05                                                                             0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          129                                                                              0.97                                                                             0.03                                                                             0.94  0  0.05                                                                             0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          130                                                                              0.97                                                                             0.03                                                                             0.94  0  0.05                                                                             0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          131                                                                              0.97                                                                             0.03                                                                             0.94  0  0.05                                                                             0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          132                                                                              0.97                                                                             0.03                                                                             0.94  0  0.05                                                                             0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          133                                                                              0.97                                                                             0.03                                                                             0.94  0  0.05                                                                             0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          134                                                                              0.97                                                                             0.03                                                                             0.94  0  0.05                                                                             0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          135                                                                              0.97                                                                             0.03                                                                             0.94  0  0.05                                                                             0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          136                                                                              0.97                                                                             0.03                                                                             0.94  0  0.05                                                                             0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          137                                                                              0.97                                                                             0.03                                                                             0.94  0  0.05                                                                             0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          138                                                                              0.97                                                                             0.03                                                                             0.94  0  0.05                                                                             0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          139                                                                              0.97                                                                             0.03                                                                             0.94  0  0.05                                                                             0.05                                                                             0  0.05                                                                             0.05                                                                             0.1                                          140                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         141                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         142                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         143                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         144                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         145                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         146                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         147                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         148                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         149                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         150                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         151                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         152                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         153                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         154                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         155                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         156                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         157                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         158                                                                              0.98                                                                             0.02                                                                             0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.06                                         159                                                                              0.995                                                                            0.005                                                                            0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.08                                         160                                                                              0.995                                                                            0.005                                                                            0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.08                                         161                                                                              0.995                                                                            0.005                                                                            0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.08                                         162                                                                              0.98                                                                             0.005                                                                            0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.08                                         163                                                                              0.995                                                                            0.005                                                                            0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.08                                         164                                                                              0.995                                                                            0.005                                                                            0.96  0.02                                                                             0.02                                                                             0.04                                                                             0.02                                                                             0.02                                                                             0.04                                                                             0.08                                         165                                                                              0.96                                                                             0.04                                                                             0.98  0.02                                                                             0.01                                                                             0.03                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.05                                         166                                                                              0.96                                                                             0.04                                                                             0.98  0.02                                                                             0.01                                                                             0.03                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.05                                         167                                                                              0.96                                                                             0.04                                                                             0.98  0.02                                                                             0.01                                                                             0.03                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.05                                         168                                                                              0.96                                                                             0.04                                                                             0.98  0.02                                                                             0.01                                                                             0.03                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.05                                         169                                                                              0.96                                                                             0.04                                                                             0.98  0.02                                                                             0.01                                                                             0.03                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.05                                         170                                                                              0.96                                                                             0.04                                                                             0.98  0.02                                                                             0.01                                                                             0.03                                                                             0.01                                                                             0.01                                                                             0.02                                                                             0.05                                         __________________________________________________________________________

                  TABLE 2                                                         ______________________________________                                        Caramic Compositions                                                          Major Ingredient                                                              Test y                                                                        No.  Sc     Y      Gd   Dy   Ho   Er   Yb   Sum  k                            ______________________________________                                         1   0      0      0    0    0    0    0.01 0.01 1.02                          2   0      0      0    0    0    0    0.01 0.01 1.02                          3   0      0      0    0    0    0    0.01 0.01 1.02                          4   0      0      0    0    0    0    0.01 0.01 1.02                          5   0      0      0    0    0    0    0.01 0.01 1.02                          6   0      0      0    0    0    0    0.01 0.01 1.02                          7   0      0      0    0    0    0    0.01 0.01 1.02                          8   0      0      0    0    0    0    0.01 0.01 1.02                          9   0      0      0    0    0    0    0.01 0.01 1.02                         10   0      0      0    0    0    0    0.01 0.01 1.02                         11   0      0      0    0    0    0    0.01 0.01 1.02                         12   0      0      0    0    0    0    0.01 0.01 1.02                         13   0      0      0    0    0    0    0.01 0.01 1.02                         14   0      0      0    0    0    0    0.01 0.01 1.02                         15   0      0      0    0    0    0    0.01 0.01 1.02                         16   0      0      0    0    0    0    0.01 0.01 1.02                         17   0      0      0    0    0    0    0.01 0.01 1.02                         18   0      0      0    0    0    0    0.01 0.01 1.02                         19   0      0      0    0    0    0    0.01 0.01 1.02                         20   0      0      0    0    0    0    0.01 0.01 1.02                         21   0      0      0    0    0    0    0.01 0.01 1.02                         22   0      0      0    0    0    0    0.01 0.01 1.02                         23   0      0      0    0    0    0    0.01 0.01 1.02                         24   0.01   0      0    0    0    0    0    0.01 1.02                         25   0.01   0      0    0    0    0    0    0.01 1.02                         26   0.01   0      0    0    0    0    0    0.01 1.02                         27   0      0.01   0    0    0    0    0    0.01 1.02                         28   0      0.01   0    0    0    0    0    0.01 1.02                         29   0      0.01   0    0    0    0    0    0.01 1.02                         30   0      0      0.01 0    0    0    0    0.01 1.02                         31   0      0      0.01 0    0    0    0    0.01 1.02                         32   0      0      0.01 0    0    0    0    0.01 1.02                         33   0      0      0    0.01 0    0    0    0.01 1.02                         34   0      0      0    0.01 0    0    0    0.01 1.02                         35   0      0      0    0.01 0    0    0    0.01 1.02                         36   0      0      0    0    0.01 0    0    0.01 1.02                         37   0      0      0    0    0.01 0    0    0.01 1.02                         38   0      0      0    0    0.01 0    0    0.01 1.02                         39   0      0      0    0    0    0.01 0    0.01 1.02                         40   0      0      0    0    0    0.01 0    0.01 1.02                         41   0      0      0    0    0    0.01 0    0.01 1.02                         42   0      0      0    0    0    0    0.01 0.01 1.02                         43   0      0      0    0    0    0    0.01 0.01 1.02                         44   0      0      0    0    0    0    0.01 0.01 1.02                         45   0      0      0    0    0    0    0.01 0.01 1.02                         46   0      0      0    0    0    0    0.01 0.01 1.02                         47   0      0      0    0    0    0    0.01 0.01 1.02                         48   0      0      0    0.01 0    0    0    0.01 1.04                         49   0      0      0    0.01 0    0    0    0.01 1.04                         50   0      0      0    0.01 0    0    0    0.01 1.04                         51   0      0      0    0.01 0    0    0    0.01 1.04                         52   0      0      0    0.01 0    0    0    0.01 1.04                         53   0      0      0    0.01 0    0    0    0.01 1.04                         54   0      0      0    0    0    0    0    0    1.04                         55   0      0      0    0    0    0    0.005                                                                              0.005                                                                              1.04                         56   0      0      0    0    0    0    0.01 0.01 1.04                         57   0      0      0    0    0    0    0.02 0.02 1.04                         58   0      0      0    0    0    0    0.04 0.04 1.04                         59   0      0      0    0    0    0    0.06 0.06 1.04                         60   0.005  0      0    0    0    0    0    0.005                                                                              1.04                         61   0.04   0      0    0    0    0    0    0.04 1.04                         62   0.06   0      0    0    0    0    0    0.06 1.04                         63   0      0.005  0    0    0    0    0    0.005                                                                              1.04                         64   0      0.04   0    0    0    0    0    0.04 1.04                         65   0      0.06   0    0    0    0    0    0.06 1.04                         66   0      0      0.005                                                                              0    0    0    0    0.005                                                                              1.04                         67   0      0      0.04 0    0    0    0    0.04 1.04                         68   0      0      0.06 0    0    0    0    0.06 1.04                         69   0      0      0    0.005                                                                              0    0    0    0.005                                                                              1.04                         70   0      0      0    0.04 0    0    0    0.04 1.04                         71   0      0      0    0.06 0    0    0    0.06 1.04                         72   0      0      0    0    0.005                                                                              0    0    0.005                                                                              1.04                         73   0      0      0    0    0.04 0    0    0.04 1.04                         74   0      0      0    0    0.06 0    0    0.06 1.04                         75   0      0      0    0    0    0.005                                                                              0    0.005                                                                              1.04                         76   0      0      0    0    0    0.04 0    0.04 1.04                         77   0      0      0    0    0    0.06 0    0.06 1.04                         78   0      0      0    0    0    0    0.02 0.02 1.01                         79   0      0      0    0    0    0    0.02 0.02 1.01                         80   0      0      0    0    0    0    0.02 0.02 1.01                         81   0      0      0    0    0    0    0.02 0.02 1.01                         82   0      0      0    0    0    0    0.02 0.02 1.01                         83   0      0      0    0.005                                                                              0    0    0    0.005                                                                              1.04                         84   0      0      0    0.005                                                                              0    0    0    0.005                                                                              1.04                         85   0      0      0    0.005                                                                              0    0    0    0.005                                                                              1.04                         86   0      0      0    0.005                                                                              0    0    0    0.005                                                                              1.04                         87   0      0      0    0.005                                                                              0    0    0    0.005                                                                              1.04                         88   0      0      0    0    0    0    0.02 0.02 1                            89   0      0      0    0    0    0    0.02 0.02 1                            90   0      0      0    0    0    0    0.02 0.02 1                            91   0      0      0    0    0    0    0.02 0.02 1                            92   0      0      0    0    0    0    0.02 0.02 1                            93   0      0      0    0    0    0    0.02 0.02 1                            94   0      0      0    0    0    0    0.02 0.02 1                            95   0      0      0    0    0    0    0.02 0.02 1                            96   0      0      0    0    0    0    0.02 0.02 1                            97   0      0      0    0    0    0    0.02 0.02 1                            98   0      0      0    0    0    0    0.02 0.02 1                            99   0      0      0    0    0    0    0.02 0.02 1                            100  0      0      0    0    0    0    0.02 0.02 1                            101  0      0      0    0    0    0    0.02 0.02 1                            102  0      0      0    0    0    0    0.02 0.02 1                            103  0      0      0    0    0    0    0.02 0.02 1                            104  0      0      0    0    0    0    0.02 0.02 1                            105  0      0      0    0    0    0    0.02 0.02 1                            106  0      0      0    0.04 0    0    0    0.04 1                            107  0      0      0    0.04 0    0    0    0.04 1.05                         108  0      0      0    0.04 0    0    0    0.04 1.05                         109  0      0      0    0.04 0    0    0    0.04 1.05                         110  0      0      0    0.04 0    0    0    0.04 1.05                         111  0      0      0    0.04 0    0    0    0.04 1.05                         112  0      0      0    0.04 0    0    0    0.04 1.05                         113  0      0      0    0    0    0    0.005                                                                              0.005                                                                              0.98                         114  0      0      0    0    0    0    0.005                                                                              0.005                                                                              1                            115  0      0      0    0    0    0    0.005                                                                              0.005                                                                              1.03                         116  0      0      0    0    0    0    0.005                                                                              0.005                                                                              1.05                         117  0      0      0    0    0    0    0.005                                                                              0.005                                                                              1.07                         118  0      0      0    0.02 0    0    0    0.02 0.98                         119  0      0      0    0.02 0    0    0    0.02 1                            120  0      0      0    0.02 0    0    0    0.02 1.03                         121  0      0      0    0.02 0    0    0    0.02 1.05                         122  0      0      0    0.02 0    0    0    0.02 1.07                         123  0      0      0    0.001                                                                              0    0    0.001                                                                              0.002                                                                              1.02                         124  0      0      0    0.005                                                                              0    0    0.005                                                                              0.01 1.02                         125  0      0      0    0.01 0    0    0.01 0.02 1.02                         126  0      0      0    0.02 0    0    0.02 0.04 1.02                         127  0      0      0    0.03 0    0    0.03 0.06 1.02                         128  0      0      0    0.03 0    0    0.01 0.04 1.04                         129  0      0.01   0    0    0    0    0.01 0.02 1.04                         130  0.01   0      0    0    0.01 0    0    0.02 1.04                         131  0      0.02   0    0.02 0    0    0    0.04 1.04                         132  0      0      0    0    0    0.03 0.01 0.04 1.04                         133  0      0.01   0    0.01 0    0    0.01 0.03 1.04                         134  0.01   0      0    0.02 0    0    0.01 0.04 1.04                         135  0      0.005  0.005                                                                              0.01 0.01 0.01 0    0.04 1.04                         136  0.01   0.01   0    0.01 0    0    0.01 0.04 1.04                         137  0.005  0.005  0    0.005                                                                              0    0.005                                                                              0.005                                                                              0.025                                                                              1.04                         138  0.002  0.005  0.003                                                                              0.005                                                                              0.005                                                                              0.005                                                                              0.005                                                                              0.03 1.04                         139  0.01   0.005  0.005                                                                              0.01 0.01 0.01 0.01 0.06 1.04                         140  0      0      0    0    0    0    0.01 0.01 1.02                         141  0      0      0    0    0    0    0.01 0.01 1.02                         142  0      0      0    0    0    0    0.01 0.01 1.02                         143  0      0      0    0    0    0    0.01 0.01 1.02                         144  0      0      0    0    0    0    0.01 0.01 1.02                         145  0      0      0    0    0    0    0.01 0.01 1.02                         146  0      0      0    0    0    0    0.01 0.01 1.02                         147  0      0      0    0    0    0    0.01 0.01 1.02                         148  0      0      0    0    0    0    0.01 0.01 1.02                         149  0      0      0    0    0    0    0.01 0.01 1.02                         150  0      0      0    0    0    0    0.01 0.01 1.02                         151  0      0      0    0    0    0    0.01 0.01 1.02                         152  0      0      0    0    0    0    0.01 0.01 1.02                         153  0      0      0    0    0    0    0.01 0.01 1.02                         154  0      0      0    0    0    0    0.01 0.01 1.02                         155  0      0      0    0    0    0    0.01 0.01 1.02                         156  0      0      0    0    0    0    0.01 0.01 1.02                         157  0      0      0    0    0    0    0.01 0.01 1.02                         158  0      0      0    0    0    0    0.01 0.01 1.02                         159  0      0      0    0    0    0    0.01 0.01 1.04                         160  0      0      0    0    0    0    0.01 0.01 1.04                         161  0      0      0    0    0    0    0.01 0.01 1.04                         162  0      0      0    0    0    0    0.01 0.01 1.04                         163  0      0      0    0    0    0    0.01 0.01 1.04                         164  0      0      0    0    0    0    0.01 0.01 1.04                         165  0      0      0    0.01 0    0    0    0.01 1.03                         166  0      0      0    0.01 0    0    0    0.01 1.03                         167  0      0      0    0.01 0    0    0    0.01 1.03                         168  0      0      0    0.01 0    0    0    0.01 1.03                         169  0      0      0    0.01 0    0    0    0.01 1.03                         170  0      0      0    0.01 0    0    0    0.01 1.03                         ______________________________________                                    

                                      TABLE 3                                     __________________________________________________________________________    Ceramic Compositions                                                          Additive Ingredient                                                                     Composition                                                         Test                                                                              Proportion                                                                          (mole %)    (mole %)                                                No. (wt. parts)                                                                         B.sub.2 O.sub.3                                                                  Li.sub.2 O                                                                       SiO.sub.2                                                                        MO BaO                                                                              SrO                                                                              CaO                                                                              MgO                                                                              ZnO                                         __________________________________________________________________________     1  2     --  1 80 19 20 0  50 30 0                                            2  2     --  1 39 60 20 0  50 30 0                                            3  2     -- 30 30 40 20 0  50 30 0                                            4  2     -- 50 50  0 0  0  0   0 0                                            5  2     -- 20 80  0 0  0  0   0 0                                            6  2     -- 10 50 40 20 0  50 30 0                                            7  2     -- 30 40 30 20 0  50 30 0                                            8  2     -- 20 60 20 20 0  50 30 0                                            9  2     -- 35 65  0 0  0  0   0 0                                           10  2     --  1 59 40 20 0  50 30 0                                           11  2     --  1 85 14 20 0  50 30 0                                           12  2     -- 20 29 51 20 0  50 30 0                                           13  2     -- 50 30 20 20 0  50 30 0                                           14  2     -- 60 30 10 20 0  50 30 0                                           15  2     -- 60 40  0 0  0  0   0 0                                           16  2     -- 10 90  0 0  0  0   0 0                                           17  2     -- 20 60 20 100                                                                              0  0   0 0                                           18  2     -- 20 60 20 0  100                                                                              0   0 0                                           19  2     -- 20 60 20 0  0  100                                                                               0 0                                           20  2     -- 20 60 20 0  0  0  100                                                                              0                                           21  2     -- 20 60 20 0  0  0   0 100                                         22  2     -- 20 60 20 20 20 20 20 20                                          23  2     -- 20 60 20 40 10 20 10 20                                          24  2     -- 10 50 40 40 20 0  50 30                                          25  2     -- 20 60 20 20 20 0  50 30                                          26  2     -- 35 65  0 0  0  0   0 0                                           27  2     -- 10 50 40 40 20 0  50 30                                          28  2     -- 20 60 20 20 20 0  50 30                                          29  2     -- 35 65  0 0  0  0   0 0                                           30  2     -- 10 50 40 40 20 0  50 30                                          31  2     -- 20 60 20 20 20 0  50 30                                          32  2     -- 35 65  0 0  0  0   0 0                                           33  2     -- 10 50 40 40 20 0  50 30                                          34  2     -- 20 60 20 20 20 0  50 30                                          35  2     -- 35 65  0 0  0  0   0 0                                           36  2     -- 10 50 40 40 20 0  50 30                                          37  2     -- 20 60 20 20 20 0  50 30                                          38  2     -- 35 65  0 0  0  0   0 0                                           39  2     -- 10 50 40 40 20 0  50 30                                          40  2     -- 20 60 20 20 20 0  50 30                                          41  2     -- 35 65  0 0  0  0   0 0                                           42  0     --  0  0  0 0  0  0   0 0                                           43  0.2   -- 15 75 10 30 10 10 30 20                                          44  1     -- 15 75 10 30 10 10 30 20                                          45  3     -- 15 75 10 30 10 10 30 20                                          46  5     -- 15 75 10 30 10 10 30 20                                          47  7     -- 15 75 10 30 10 10 30 20                                          48  0     --  0  0 100                                                                              0  0  0   0 0                                           49  0.2   -- 15 40 45 20 20 20 20 20                                          50  1     -- 15 40 45 20 20 20 20 20                                          51  3     -- 15 40 45 20 20 20 20 20                                          52  5     -- 15 40 45 20 20 20 20 20                                          53  7     -- 15 40 45 20 20 20 20 20                                          54  1     -- 30 40 30 0  0  0  100                                                                              0                                           55  1     -- 30 40 30 0  0  0  100                                                                              0                                           56  1     -- 30 40 30 0  0  0  100                                                                              0                                           57  1     -- 30 40 30 0  0  0  100                                                                              0                                           58  1     -- 30 40 30 0  0  0  100                                                                              0                                           59  1     -- 30 40 30 0  0  0  100                                                                              0                                           60  1     -- 30 40 30 0  0  0  100                                                                              0                                           61  1     -- 30 40 30 0  0  0  100                                                                              0                                           62  1     -- 30 40 30 0  0  0  100                                                                              0                                           63  1     -- 30 40 30 0  0  0  100                                                                              0                                           64  1     -- 30 40 30 0  0  0  100                                                                              0                                           65  1     -- 30 40 30 0  0  0  100                                                                              0                                           66  1     -- 30 40 30 0  0  0  100                                                                              0                                           67  1     -- 30 40 30 0  0  0  100                                                                              0                                           68  1     -- 30 40 30 0  0  0  100                                                                              0                                           69  1     -- 30 40 30 0  0  0  100                                                                              0                                           70  1     -- 30 40 30 0  0  0  100                                                                              0                                           71  1     -- 30 40 30 0  0  0  100                                                                              0                                           72  1     -- 30 40 30 0  0  0  100                                                                              0                                           73  1     -- 30 40 30 0  0  0  100                                                                              0                                           74  1     -- 30 40 30 0  0  0  100                                                                              0                                           75  1     -- 30 40 30 0  0  0  100                                                                              0                                           76  1     -- 30 40 30 0  0  0  100                                                                              0                                           77  1     -- 30 40 30 0  0  0  100                                                                              0                                           78  3     -- 10 50 40 20 20 20 20 20                                          79  3     -- 10 50 40 20 20 20 20 20                                          80  3     -- 10 50 40 20 20 20 20 20                                          81  3     -- 10 50 40 20 20 20 20 20                                          82  3     -- 10 50 40 20 20 20 20 20                                          83  1     -- 20 60 20 0  100                                                                              0   0 0                                           84  1     -- 20 60 20 0  100                                                                              0   0 0                                           85  1     -- 20 60 20 0  100                                                                              0   0 0                                           86  1     -- 20 60 20 0  100                                                                              0   0 0                                           87  1     -- 20 60 20 0  100                                                                              0   0 0                                           88  0.5   -- 30 40 30 0  0  0  100                                                                              0                                           89  0.5   -- 30 40 30 0  0  0  100                                                                              0                                           90  0.5   -- 30 40 30 0  0  0  100                                                                              0                                           91  0.5   -- 30 40 30 0  0  0  100                                                                              0                                           92  0.5   -- 30 40 30 0  0  0  100                                                                              0                                           93  0.5   -- 30 40 30 0  0  0  100                                                                              0                                           94  0.5   -- 30 40 30 0  0  0  100                                                                              0                                           95  0.5   -- 30 40 30 0  0  0  100                                                                              0                                           96  0.5   -- 30 40 30 0  0  0  100                                                                              0                                           97  0.5   -- 30 40 30 0  0  0  100                                                                              0                                           98  0.5   -- 30 40 30 0  0  0  100                                                                              0                                           99  0.5   -- 30 40 30 0  0  0  100                                                                              0                                           100 0.5   -- 30 40 30 0  0  0  100                                                                              0                                           101 0.5   -- 30 40 30 0  0  0  100                                                                              0                                           102 0.5   -- 30 40 30 0  0  0  100                                                                              0                                           103 0.5   -- 30 40 30 0  0  0  100                                                                              0                                           104 0.5   -- 30 40 30 0  0  0  100                                                                              0                                           105 0.5   -- 30 40 30 0  0  0  100                                                                              0                                           106 0.5   -- 30 40 30 0  0  0  100                                                                              0                                           107 3     -- 35 55 10 100                                                                              0  0   0 0                                           108 3     -- 35 55  3 100                                                                              0  0   0 0                                           109 3     -- 35 55  3 100                                                                              0  0   0 0                                           110 3     -- 35 55  3 100                                                                              0  0   0 0                                           111 3     -- 35 55  3 100                                                                              0  0   0 0                                           112 3     -- 35 55  3 100                                                                              0  0   0 0                                           113 1     -- 10 50 40 20 20 20 20 20                                          114 1     -- 10 50 40 20 20 20 20 20                                          115 1     -- 10 50 40 20 20 20 20 20                                          116 1     -- 10 50 40 20 20 20 20 20                                          117 1     -- 10 50 40 20 20 20 20 20                                          118 2     -- 15 75 10 0  0  100                                                                               0 0                                           119 2     -- 15 75 10 0  0  100                                                                               0 0                                           120 2     -- 15 75 10 0  0  100                                                                               0 0                                           121 2     -- 15 75 10 0  0  100                                                                               0 0                                           122 2     -- 15 75 10 0  0  100                                                                               0 0                                           123 0.5   -- 30 55 15 20 20 20 20 20                                          124 0.5   -- 30 55 15 20 20 20 20 20                                          125 0.5   -- 30 55 15 20 20 20 20 20                                          126 0.5   -- 30 55 15 20 20 20 20 20                                          127 0.5   -- 30 55 15 20 20 20 20 20                                          128 5     -- 35 40 25 20 0  30 50 0                                           129 5     -- 35 40 25 20 0  30 50 0                                           130 5     -- 35 40 25 20 0  30 50 0                                           131 5     -- 35 40 25 20 0  30 50 0                                           132 5     -- 35 40 25 20 0  30 50 0                                           133 5     -- 35 40 25 20 0  30 50 0                                           134 5     -- 35 40 25 20 0  30 50 0                                           135 5     -- 35 40 25 20 0  30 50 0                                           136 5     -- 35 40 25 20 0  30 50 0                                           137 5     -- 35 40 25 20 0  30 50 0                                           138 5     -- 35 40 25 20 0  30 50 0                                           139 5     -- 35 40 25 20 0  30 50 0                                           140 2      1 -- 80 19 20 0  50 30 0                                           141 2      1 -- 39 60 20 0  50 30 0                                           142 2     30 --  0 70 20 0  50 30 0                                           143 2     90 --  0 10 20 0  50 30 0                                           144 2     90 -- 10  0 0  0  0   0 0                                           145 2     20 -- 80  0 0  0  0   0 0                                           146 2     15 -- 30 55 20 0  50 30 0                                           147 2     45 -- 15 40 20 0  50 30 0                                           148 2     20 -- 50 30 20 0  50 30 0                                           149 2     50 -- 30 20 20 0  50 30 0                                           150 2     10 -- 20 70 20 0  50 30 0                                           151 2     95 --  5  0 0  0  0   0 0                                           152 2     10 -- 85  5 20 0  50 30 0                                           153 2     20 -- 50 30 100                                                                              0  0   0 0                                           154 2     20 -- 50 30 0  0  0   0 0                                           155 2     20 -- 50 30 0  0  100                                                                               0 0                                           156 2     20 -- 50 30 0  0  0  100                                                                              0                                           157 2     20 -- 50 30 0  0  0   0 100                                         158 2     20 -- 50 30 20 20 20 20 20                                          159 0      0 --  0  0 0  0  0   0 0                                           160 0.2   15 -- 75 10 0  50 0  50 30                                          161 1     15 -- 75 10 0  50 0  50 30                                          162 3     15 -- 75 10 0  50 0  50 30                                          163 5     15 -- 75 10 0  50 0  50 30                                          164 7     15 -- 75 10 0  50 0  50 30                                          165 0      0 --  0  0 0  0  0   0 0                                           166 0.2   45 -- 15 40 20 20 20 20 20                                          167 1     45 -- 15 40 20 20 20 20 20                                          168 3     45 -- 15 40 20 20 20 20 20                                          169 5     45 -- 15 40 20 20 20 20 20                                          170 7     45 -- 15 40 20 20 20 20 20                                          __________________________________________________________________________

According to Tables 1 and 2, the major ingredient of the dielectricbodies of the capacitors of Test No. 1 was:

    0.98{(Ba.sub.0.96 M.sub.0.05 L.sub.0.01)O.sub.1.02 (Ti.sub.0.99 R.sub.0.01)O.sub.1.995 }+0.02CaZrO.sub.3

or, more specifically, since M₀.05 =Mg₀.05, L₀.01 =Sr₀.01, and R₀.01=Yb₀.01,

    0.98{(Ba.sub.0.96 Mg.sub.0.05 Sr.sub.0.01)O.sub.1.02 (Ti.sub.0.99 Yb.sub.0.01)O.sub.1.995 }+0.02CaZrO.sub.3

One hundred parts by weight of this major ingredient was admixed with2.0 parts by weight of an additive ingredients of one mole percent Li₂O, 80 mole percent SiO₂ and 19 mole percent MO. The MO was a mixture of20 mole percent BaO, 50 mole percent CaO, and 30 mole percent MgO.

For the fabrication of the capacitors of Test No. 1 we started with thepreparation of the first component, (Ba₀.96 Mg₀.05 Sr₀.01)O₁.02 (Ti₀.99Yb₀.01)O₁.995, of the major ingredient. We prepared the following startmaterials for the first component of the major ingredient:

Barium carbonate (BaCO₃): 1044.06 grams (0.96 mole part)

Magnesium oxide (MgO): 11.11 grams (0.05 mole part)

Strontium oxide (SrO) 5.71 grams (0.01 mole part)

Titanium oxide (TiO₂): 435.94 grams (0.99 mole part)

Yttrebium oxide (Yb₂ O₃) 10.84 grams (0.005 mole part)

These start materials had all purities of not less than 99.0 percent.The above specified weights of the start materials do not include thoseof the impurities contained.

We charged the start materials into a pot mill together with aluminaballs and 2.5 liters of water and intimately intermingled them bystirring the pot mill for 15 hours. Then we introduced the mixture intoa stainless steel pot and dried it by air heated to 150 degrees C. forfour hours. Then we crushed the dried mixture into relatively coarseparticles and then fired the particles in air within a tunnel furnace at1200 degrees C. for two hours. There was thus obtained the firstcomponent of the major ingredient in finely divided form.

Then we proceeded to the preparation of the second component, CaZrO₃, ofthe major ingredient of Test No. 1. We intermingled 448.96 grams ofcalcium carbonate (CaCO₃) and 551.04 grams at zirconium oxide (ZrO₂).Then we dried and pulverized the mixture and fired the resultingparticles in air at 1250 degrees C. for two hours.

Then, in order to obtain the major ingredient of Test No. 1 in therequired molar ratio (0.98:0.02) of the first and second components, weintermingled 984.34 grams (98 mole parts) of (Ba₀.96 Mg₀.05 Sr₀.01)O₁.02(Ti₀.99 Yb₀.01)O₁.995 and 15.66 grams (two mole parts) of CaZrO₃. Onethousand grams of the major ingredient was thus obtained in finelydivided form.

Then, in order to obtain the additive ingredients of Test No. 1 we firstprepared the following substances in the following amounts:

    ______________________________________                                        Li.sub.2 O      0.44 grams (1.0 mole part)                                    SiO.sub.2      70.99 grams (80.0 mole parts)                                  BaCO.sub.3     11.10 grams (3.8 mole parts)                                   CaCO.sub.3     14.70 grams (9.5 mole parts)                                   MgO             3.40 grams (5.7 mole parts)                                   ______________________________________                                    

To these substances we added 300 cubic centimeters of alcohol andstirred the resulting slurry for 10 hours in a polyethylene pot withalumina balls. Then we air fired the mixture at 1000 degrees C. for twohours. Then we charged the fired mixture into an alumina pot togetherwith 300 cubic centimeters of water and pulverized it with alumina ballsover a period of 15 hours. Then we dried the pulverized mixture at 150degrees C. for four hours.

Thus we obtained in finely divided form the desired additive mixture ofone mole percent Li₂ O, 80 mole percent SiO₂ and 19 mole percent MO,with the MO consisting of 3.8 mole percent BaO, 9.5 mole percent CaO,and 5.7 mole percent MgO. The relative proportions of BaO, CaO, and MgOwere 20, 50 and 30 mole percent.

Then, we added 20 grams (two weight parts) of the additive ingredient to1000 grams (100 weight parts) of the major ingredient. Further, to thismixture, we added 15 percent by weight of an organic binder and 50percent by weight of water with respect to the total weight of the majoringredient and additives. The organic binder was an aqueous solution ofacrylic ester polymer, glycerine, and condensed phosphate. Then we ballmilled the mixture into a slurry and then defoamed it in vacuum.

Then we charged the defoamed slurry into a reverse roll coater andshaped it into a thin, continuous strip on an elongate backing strip ofpolyester film. Then we dried the strip by heating it to 100 degrees C.on the backing film. There was thus obtained a green ceramic strip witha thickness of approximately 25 micrometers. We subsequently punched itinto "squares" sized 10 by 10 centimeters. These green ceramic squareswere to become the ceramic layers 12, FIG. 1, in the completed testcapacitors 10.

For the fabrication of the base metal film electrodes 14 on the ceramiclayers 12, we prepared 10 grams of nickel in finely divided form, withan average particle size of 1.5 micrometers, and a solution of 0.9 gramsof ethyl cellulose in 9.1 grams of butyl "Carbitol" (trademark fordiethylene glycol monobutyl ether). We intimately intermingled them inan agitator for 10 hours, thereby providing an electroconductive paste.Then we "printed" the paste on one surface of each green ceramic square,which had been prepared as above stated, through a screen having anarray of 50 perforations of rectangular shape, each sized seven by 14millimeters.

After having allowed the printed paste to dry, we stacked two greensquares, with the printings thereon directed upwardly, and with theprintings on the two squares offset from each other to an extentapproximately half the pitch of the paste pattern in the longitudinaldirection. Then we placed the stack of two printed squares between twoseparate stacks of four unprinted squares each with a thickness of 60micrometers. Then we exerted a pressure of 39.2 MPa on the resultingstack of printed and unprinted squares in their thickness direction at50 degrees C., thereby firmly bonding them together. Then we cut thebonded squares in a latticed pattern into 50 laminate chips of identicalconstruction.

We employed a furnace capable of atmosphere control for cofiring theabove prepared green dielectric bodies and, buried therein, theconductive layers which were to become the film electrodes 14 in thecompleted capacitors 10. We first air heated the chips to 600 degrees C.at a rate of 100 degrees C. per hour, thereby driving off the organicbinder that had been used for providing the slurry of the powdered majoringredient and additives. Then we changed the furnace atmosphere fromair to a reductive (nonoxidative) atmosphere consisting of two percentby volume of molecular hydroge and 98 percent by volume of molecularnitrogen. Then, in this furnace atmosphere, we raised the furnacetemperature from 600 degrees C. to 1150 degrees C. at a rate of 100degrees C. per hour. We maintained for three hours the maximum furnacetemperature of 1150 degrees C., at which the ceramic bodies formulatedan accordance with our invention were to be sintered to maturity. Thenwe lowered the furnace temperataure to 600 degrees C. at a rate of 100degrees C. per hour. Then, with the furnace atmosphere again changed toair (oxidative atmosphere), we maintained the temperature of 600 degreesC. fo 30 minutes for the oxidizing heat treatment of the sintered chips.Then we allowed the furnace temperature to drop to room temperature.

Thus we obtained the dielectric ceramic bodies 15 cosintered with thefilm electrodes 14 buried therein.

We proceeded to the production of the pair of conductive terminations 16on both sides of each ceramic body 15 at which were exposed the filmelectrodes 14. First, for the production of the inmost zinc layers 18,we coated both sides of each ceramic body 15 with an electroconductivepaste composed of zinc, glass frit and vehicle. Then, after havingallowed the coatings to dry, we heated them to 550 degrees C. in air andheld the temperature for 15 minutes, thereby completing the zinc layers18 each in direct contact with one of the two film electrodes 14. Thenwe formed the intermediate copper layers 20 over the zinc layers 18 byelectroless plating, and then the outermost solder layers 22 over thecopper layers 20 by electroplating an alloy of lead and tin.

We have thus completed the fabrication of the monolithic, multilayeredceramic test capacitors 10, each constructed as in FIG. 1, in accordancewith the ceramic composition of Test No. 1 of Tables 1, 2 and 3. Thecomposition of the ceramic bodies 15 of the thus completed capacitors 10proved substantially akin to that before sintering.

As for the other ceramic compositions of Tables 1, 2 and 3 designatedTests Nos. 2-170, we made similar capacitors through the same procedureas set forth in the foregoing in connection with the Test No. 1composition, except for the temperature of sintering in the reductiveatmosphere, to which we will presently refer in more detail.

Then we tested all the capacitors of Tests Nos. 1-170 as to theirspecific dielectric constants, dielectric losses, resistivities, andcapacitance-temperature characteristics. We measured these electricalproperties of the test capacitors by the following methods:

Specific Dielectric Constant

The capacitance of each test capacitor was first measured at atemperature of 20 degrees C., a frequency of one kilohertz, and aneffective voltage of 1.0 volt. Then the specific dielectric constant wascomputed from the measured value of capacitance, and the area (25 squaremillimeters) of each of the opposed parts of the film electrodes 14, andthe thickness (0.02 millimeter) of that ceramic layer 12 whichintervenes between the film electrodes.

Dielectric Loss

The dielectric loss was measured under the same conditions as thespecific constant.

Resistivity

Resistance between the pair of conductive terminations 16 of each testcapacitor was measured after the application of a direct voltage of 100volts for one minute. Then the resistivity was computed from themeasured resistance value and the size of each test capacitor.

Temperature Dependence of Capacitance

The test capacitors were introduced into a thermostatic oven, and theircapacitances at various preselected temperatures were measured at afrequency of one kilohertz and an effective voltage of 1.0 volt. Thenthe percent changes of the capacitances at -55 degrees and +125 degreesC. from those at 25 degrees C., and at -25 degrees and +85 degrees C.from those at 20 degrees C., were computed.

Table 4 gives the properties of the test capacitors as measured by theabove described methods, as well as the maximum temperatures at whichthe test capacitors were sintered in the reductive atmosphere duringtheir manufacture.

                                      TABLE 4                                     __________________________________________________________________________    Firing Temperature & Capacitor Characteristics                                       Capacitor Characteristics                                                 Firing                                                                            Specific                                                                            Dielectric                                                       Test                                                                             Temp.                                                                             Dielectric                                                                          Loss  Resistivity                                                                          Capacitance Variations (%)                          No.                                                                              (°C.)                                                                      Constant                                                                            (%)   (megohm-cm)                                                                          At -55° C.                                                                   At 125° C.                                                                   At -25° C.                                                                   At 85° C.                  __________________________________________________________________________     1 1150                                                                              3920  1.1   5.6 × 10.sup.6                                                                 -10.2 3.0   -5.3  -6.0                               2 1150                                                                              3900  1.0   7.4 × 10.sup.6                                                                  -8.9 1.5   -4.1  -7.1                               3 1140                                                                              3870  1.0   4.9 × 10.sup.6                                                                  -9.7 4.5   -5.5  -5.1                               4 1150                                                                              3920  1.2   4.9 × 10.sup.6                                                                 -10.9 5.0   -6.1  -4.6                               5 1130                                                                              3900  1.2   4.7 × 10.sup.6                                                                 -10.9 5.7   -6.2  -4.2                               6 1140                                                                              3940  1.1   5.1 × 10.sup.6                                                                 -10.0 2.9   -5.5  -5.6                               7 1130                                                                              3940  1.0   4.3 × 10.sup.6                                                                 -10.4 3.7   -5.6  -6.0                                8                                                                              1120                                                                              3830  1.1   5.9 × 10.sup.6                                                                 -10.7 5.2   -5.8  -5.0                               9 1160                                                                              3950  1.0   4.5 × 10.sup.6                                                                 -11.2 4.7   -6.3  -3.8                              10 1130                                                                              3830  1.1   4.4 × 10.sup.6                                                                 -10.6 3.4   -5.8  -6.2                              11 1250                                                                              Not coherently bonded on firing                                        12 1250                                                                              "                                                                      13 1250                                                                              "                                                                      14 1250                                                                              "                                                                      15 1250                                                                              "                                                                      16 1250                                                                              "                                                                      17 1140                                                                              3900  1.0   5.5 × 10.sup.6                                                                 -11.2 5.3   -5.9  -5.1                              18 1140                                                                              3840  1.0   6.1 × 10.sup.6                                                                 -10.5 3.0   -6.9  -5.8                              19 1140                                                                              3890  1.1   6.3 × 10.sup.6                                                                 -11.1 4.5   -6.1  -5.1                              20 1130                                                                              3920  1.2   6.4 × 10.sup.6                                                                 -10.9 4.7   -5.9  -5.1                              21 1140                                                                              3860  1.1   6.0 × 10.sup.6                                                                 -11.0 3.4   -6.1  -5.4                              22 1130                                                                              3880  0.9   5.6 × 10.sup.6                                                                 -10.6 5.3   -5.8  -5.4                              23 1130                                                                              3920  1.1   5.6 × 10.sup.6                                                                 -10.7 4.6   -6.1  -5.0                              24 1150                                                                              3930  1.1   4.7 × 10.sup.6                                                                 -10.1 3.1   -5.4  -6.4                              25 1150                                                                              3910  1.2   4.7 × 10.sup.6                                                                  -9.7 4.3   -6.1  -5.0                              26 1150                                                                              3960  1.0   5.9 × 10.sup.6                                                                  -9.7 5.5   -4.2  -6.1                              27 1130                                                                              3860  1.0   5.3 × 10.sup.6                                                                 -10.1 2.8   -5.3  -5.0                              28 1140                                                                              3880  1.1   4.8 × 10.sup.6                                                                 -10.3 1.4   -5.1  -5.3                              29 1130                                                                              3880  1.2   4.2 × 10.sup.6                                                                  -9.6 4.2   -6.3  -6.1                              30 1140                                                                              3990  1.0   6.2 × 10.sup.6                                                                 -10.0 5.4   -5.1  -5.3                              31 1150                                                                              3900  1.1   7.7 × 10.sup.6                                                                 -10.1 3.0   -4.8  -5.6                              32 1140                                                                              3940  1.1   5.2 × 10.sup.6                                                                 -10.2 1.3   -6.1  -4.8                              33 1150                                                                              3970  1.1   4.8 × 10.sup.6                                                                 -10.1 5.5   -5.2  -4.8                              34 1140                                                                              3900  1.1   7.7 × 10.sup.6                                                                 -10.2 3.1   -5.0  -5.6                              35 1140                                                                              3910  1.2   3.9 × 10.sup.6                                                                 -10.1 1.7   -6.1  -4.5                              36 1150                                                                              3850  1.0   5.8 × 10.sup.6                                                                 -10.5 4.3   -5.6  -5.3                              37 1130                                                                              3860  1.0   5.0 × 10.sup.6                                                                 -11.1 1.2   -4.5  -4.8                              38 1130                                                                              3870  1.1   4.3 × 10.sup.6                                                                 -10.2 3.2   -5.4  -4.7                              39 1140                                                                              3940  1.0   4.6 × 10.sup.6                                                                 -10.6 1.6   -4.1  -5.1                              40 1130                                                                              3910  1.1   5.3 × 10.sup.6                                                                 -10.8 4.0   -4.0  -4.6                              41 1130                                                                              3910  1.0   3.9 × 10.sup.6                                                                 -11.0 2.9   -4.1  -5.3                              42 1250                                                                              Not coherently bonded on firing                                        43 1190                                                                              4560  1.4   1.7 × 10.sup.6                                                                 -10.5 2.6   -5.9  -5.1                              44 1160                                                                              4140  1.2   2.9 × 10.sup.6                                                                 -10.1 3.0   -5.8  -4.7                              45 1130                                                                              3540  1.0   5.9 × 10.sup.6                                                                 -11.5 -0.2  -6.5  -7.1                              46 1080                                                                              3210  1.5   3.2 × 10.sup.6                                                                 -12.7 -2.4  -7.7  -8.8                              47 1060                                                                              2830  1.8   1.7 × 10.sup.6                                                                 -17.0 -5.0  -9.9  -12.4                             48  1250                                                                             Not coherently bonded on firing                                        49 1180                                                                              4470  1.0   4.3 × 10.sup.6                                                                 -12.4 6.2   -8.4  -2.4                              50 1170                                                                              4190  1.0   6.0 × 10.sup.6                                                                 -12.3 6.7   -8.6  -1.2                              51 1150                                                                              3710  1.2   7.1 × 10.sup.6                                                                 -13.2 3.8   -8.8  -3.7                              52 1100                                                                              3150  1.7   3.6 × 10.sup.6                                                                 -14.3 1.2   -9.7  -6.0                              53 1080                                                                              2850  1.8   1.9 × 10.sup.6                                                                 -18.8 -2.2  -10.0 -7.0                              54 1170                                                                              4030  1.3   1.8 × 10.sup.6                                                                 -10.4 2.9   -6.3  -5.2                              55 1150                                                                              4130  1.2   2.8 × 10.sup.6                                                                  -9.9 3.0   -5.3  -4.2                              56 1120                                                                              4240  1.1   4.7 × 10.sup.6                                                                  -9.8 2.9   -4.3  -4.2                              57 1080                                                                              4260  1.1   6.2 × 10.sup.6                                                                  -8.3 3.1   -4.8  -3.0                              58 1150                                                                              3990  1.3   1.9 × 10.sup.6                                                                  -9.4 3.0   -5.6  -4.1                              59 1250                                                                              Not coherently bonded on firing                                        60 1130                                                                              4160   1.1  2.0 × 10.sup.6                                                                  -9.8 3.0   -4.8  -4.4                              61 1160                                                                              3970  1.2   2.4 × 10.sup.6                                                                  -9.6 3.8   -5.2  -3.9                              62 1250                                                                              Not coherently bonded on firing                                        63 1120                                                                              4110  1.0   2.7 × 10.sup.6                                                                  -9.5 3.3   -4.6  -4.3                              64 1160                                                                              4060  1.1   2.5 × 10.sup.6                                                                 -10.0 3.4   -4.9  -4.5                              65 1250                                                                              Not coherently bonded on firing                                        66 1130                                                                              4080  1.0   3.3 × 10.sup.6                                                                  -9.4 3.4   -4.9  -4.1                              67 1160                                                                              4060  1.2   2.3 × 10.sup.6                                                                  -9.7 3.4   -5.0  -4.1                              68 1250                                                                              Not coherently bonded on firing                                        69 1130                                                                              4060  1.2   3.4 × 10.sup.6                                                                  -9.7 3.4   -5.3  -3.9                              70 1160                                                                              4090  1.0   1.5 × 10.sup.6                                                                  -9.6 3.2   -5.1  -4.1                              71 1250                                                                              Not coherently bonded on firing                                        72 1160                                                                              4100  1.2   2.7 × 10.sup.6                                                                  -9.1 6.7   -5.0  -4.7                              73 1160                                                                              4040  1.1   2.2 × 10.sup.6                                                                  -9.2 7.1   -5.4  -4.4                              74 1250                                                                              Not coherently bonded on firing                                        75 1160                                                                              4040  1.1   3.3 × 10.sup.6                                                                  -9.3 1.8   -5.4  -4.2                              76 1150                                                                              4000  1.2   1.9 × 10.sup.6                                                                  -9.4 3.8   -4.7  -4.0                              77 1250                                                                              Not coherently bonded on firing                                        78 1160                                                                              3870  1.2   7.8 × 10.sup.6                                                                 -19.2 9.4   -12.1  3.7                              79 1130                                                                              3890  1.0   8.7 × 10.sup.6                                                                 -13.5 4.6   -8.4  -2.7                              80 1120                                                                              3880  1.2   6.8 × 10.sup.6                                                                 -10.9 2.4   -2.1  -6.1                              81 1120                                                                              4050  1.0   6.4 × 10.sup.6                                                                  -4.3 -3.4  -2.3  -8.8                              82 1130                                                                              3920  1.0   6.3 × 10.sup.6                                                                   1.3 -8.2  -0.6  -13.0                             83 1180                                                                              4090  1.1   6.1 × 10.sup.6                                                                 -16.7 7.3   -11.6  3.7                              84 1170                                                                              4150  1.1   6.5 × 10.sup.6                                                                 -14.3 3.4   -9.4  -2.2                              85 1160                                                                              4120  1.1   7.4 × 10.sup.6                                                                  -8.6 -1.4  -1.8  -5.4                              86 1170                                                                              4080  1.0   4.8 × 10.sup.6                                                                  -2.2 -7.0  -1.2  -8.2                              87 1160                                                                              4150  1.1   5.8 × 10.sup.6                                                                   4.3 -12.8  0.5  -11.9                             88 1160                                                                              3820  1.6   3.6 × 10.sup.6                                                                 -16.2 6.9   -11.1 -3.6                              89 1160                                                                              4180  1.1   7.9 × 10.sup.6                                                                 -12.4 7.6   -8.1  -6.4                              90 1140                                                                              4230  1.3   3.9 × 10.sup.6                                                                 -13.0 4.9   -8.2  -5.3                              91 1150                                                                              3640  1.2   4.9 × 10.sup.6                                                                 -10.5 0.2   -8.3  -5.4                              92 1160                                                                              3700  1.2   3.4 × 10.sup.6                                                                 -10.7 -0.7  -7.4  -6.2                              93 1150                                                                              3890  1.2   5.0 × 10.sup.6                                                                 -11.2 0.5   -6.1  -1.8                              94 1160                                                                              3860  1.2   4.8 × 10.sup.6                                                                 -10.8 1.0   -7.5  -2.8                              95 1150                                                                              3920  1.2   6.2 × 10.sup.6                                                                 -12.0 1.1   -7.7  -3.4                              96 1150                                                                              3810  1.0   4.2 × 10.sup.6                                                                 -13.3 1.1   -7.9  -4.3                              97 1170                                                                              3660  1.2   4.0 × 10.sup.6                                                                 -10.7 0.2   -7.6  -3.3                              98 1140                                                                              3190  1.4   3.7 × 10.sup.6                                                                 -13.3 -0.8  -8.6  -10.3                             99 1160                                                                              4070  1.0   6.4 × 10.sup.6                                                                 -11.9 4.7   -5.9  -3.9                              100                                                                              1160                                                                              4020  1.5   3.8 × 10.sup.6                                                                 -10.5 4.1   -5.9  -5.0                              101                                                                              1160                                                                              3930  1.1   7.1 × 10.sup.6                                                                 -10.6 2.6   -5.9  -7.2                              102                                                                              1200                                                                              3810  0.9   9.3 × 10.sup.6                                                                 -10.5 1.1   -5.9  -8.5                              103                                                                              1180                                                                              3640  1.5   7.7 × 10.sup.6                                                                 -12.2 1.3   -7.6  -8.0                              104                                                                              1190                                                                              3880  1.0   8.4 × 10.sup.6                                                                 -11.0 -2.6  -5.7  -11.6                             105                                                                              1170                                                                              3530  1.7   2.1 × 10.sup.6                                                                 -12.5 -3.3  - 8.2 -11.5                             106                                                                              1150                                                                              3690  1.7   1.4 × 10.sup.6                                                                 -13.9 -5.3  -8.5  -11.3                             107                                                                              1130                                                                              3430  1.2   1.6 × 10.sup.6                                                                 -12.3 6.0   -9.3   2.8                              108                                                                              1140                                                                              3650  1.7   1.4 × 10.sup.6                                                                 -12.3 4.1   -9.5   4.3                              109                                                                              1130                                                                              3710  1.2   3.3 × 10.sup.6                                                                  -4.1 2.4   -2.2  -7.2                              110                                                                              1180                                                                              3450  1.1   3.8 × 10.sup.6                                                                  -3.4 1.7   -1.5  -8.1                              111                                                                              1170                                                                              3360  1.0   4.4 × 10.sup.6                                                                  -3.6 -2.2  -1.1  -9.6                              112                                                                              1180                                                                              3280  1.2   3.0 × 10.sup.6                                                                  -3.8 -4.3  -1.8  -11.5                             113                                                                              1130                                                                              3180  2.5   5.2 × 10.sup.6                                                                 -20.9 -12.7 -15.3 -8.3                              114                                                                              1160                                                                              3830  1.0   3.9 × 10.sup.6                                                                 -12.6 6.8   -6.8  -4.5                              115                                                                              1160                                                                              3740  0.9   3.3 × 10.sup.6                                                                 -11.0 6.2   -7.2  -4.2                              116                                                                              1180                                                                              3640  1.2   5.9 × 10.sup.6                                                                 -10.0 2.4   -5.6  -5.3                              117                                                                              1250                                                                              Not coherently bonded on firing                                        118                                                                              1120                                                                              3220  3.7   4.8 × 10.sup.4                                                                 -22.1 -10.3 -15.7 -9.5                              119                                                                              1150                                                                              3730  1.1   6.5 × 10.sup.6                                                                 -12.5 6.2   -8.1  -3.3                              120                                                                              1140                                                                              3770  1.0   6.5 × 10.sup.6                                                                 -12.3 2.7   -7.7  -3.9                              121                                                                              1180                                                                              3670  1.1   8.1 × 10.sup.6                                                                 -10.2 1.2   -7.6  -3.5                              122                                                                              1250                                                                              Not coherently bonded on firing                                        123                                                                              1150                                                                              3840  1.0   1.4 × 10.sup.6                                                                 -10.7 -1.1  -5.6  -7.1                              124                                                                              1140                                                                              3950  1.1   3.3 × 10.sup.6                                                                 -10.3 -1.2  -4.9  -6.2                              125                                                                              1120                                                                              4110  1.0   4.1 × 10.sup.6                                                                  -9.3 -0.5  -4.0  -5.6                              126                                                                              1150                                                                              3840  1.0   2.5 × 10.sup.6                                                                 -10.1 -1.0  -5.2  -6.6                              127                                                                               1250                                                                             Not coherently bonded on firing                                        128                                                                              1150                                                                              3880  1.2   3.6 × 10.sup.6                                                                  -4.1 -2.8  -1.2  -7.1                              129                                                                              1130                                                                              4090  1.1   7.2 × 10.sup.6                                                                  -3.5 -2.4  -1.0  -7.4                              130                                                                              1130                                                                              4090  1.1   4.8 × 10.sup.6                                                                  -3.5 -2.4  -1.3  -6.9                              131                                                                              1140                                                                              3870  1.1   3.2 × 10.sup.6                                                                  -4.3 -3.7  -2.0  -8.7                              132                                                                              1160                                                                              3810  1.0   3.0 × 10.sup.6                                                                  -4.1 -3.5  -2.1  -8.2                              133                                                                              1140                                                                              3970  1.0   4.8 × 10.sup.6                                                                  -3.7 -2.6  -1.4  -7.8                              134                                                                              1150                                                                              3890  1.1   2.4 × 10.sup.6                                                                  -4.3 -3.6  -2.0  -8.2                              135                                                                              1160                                                                              3870  1.1   2.5 × 10.sup.6                                                                  -4.5 -3.3  -2.1  -8.0                              136                                                                              1150                                                                              3830  1.0   1.9 × 10.sup.6                                                                  -4.2 -4.0  -1.9  -8.7                              137                                                                              1120                                                                              4130  1.0   3.4 × 10.sup.6                                                                  -3.9 -2.9  -1.5  -7.8                              138                                                                              1140                                                                              4000  1.0   5.3 × 10.sup.6                                                                  -4.0 -3.2  -1.6  -8.0                              139                                                                              1250                                                                              Not coherently bonded on firing                                        140                                                                              1140                                                                              3700  1.1   3.8 × 10.sup.6                                                                 -10.2 4.3   -7.1  -3.6                              141                                                                              1130                                                                              3690  1.0   4.4 × 10.sup.6                                                                 -10.7 3.0   -4.3  -4.4                              142                                                                              1110                                                                              3640  1.0   4.7 × 10.sup.6                                                                  -9.3 2.8   -4.3  -3.8                              143                                                                              1100                                                                              3580  1.1   4.7 × 10.sup.6                                                                 -11.2 5.4   -6.1  -2.0                              144                                                                              1100                                                                              3580  1.0   4.2 × 10.sup.6                                                                 -11.4 5.7   -5.6  -1.8                              145                                                                              1110                                                                              3650  1.0   2.2 × 10.sup.6                                                                 -11.3 5.0   -4.7  -2.5                              146                                                                              1130                                                                              3780  1.2   4.5 × 10.sup.6                                                                 -10.9 2.4   -5.4  -5.9                              147                                                                              1110                                                                              3720  0.9   3.6 × 10.sup.6                                                                  -9.6 2.8   -5.8  -6.0                              148                                                                              1120                                                                              3670  1.0   4.3 × 10.sup.6                                                                  -9.6 2.8   -5.5  -5.5                              149                                                                              1120                                                                              3670  0.9   3.3 × 10.sup.6                                                                 -10.5 3.2   -7.3  -2.2                              150                                                                              1250                                                                              Not coherently bonded on firing                                        151                                                                              1250                                                                              "                                                                      152                                                                              1250                                                                              "                                                                      153                                                                              1120                                                                              3720  1.0   5.4 × 10.sup.6                                                                  -9.2 2.7   -5.0  -4.1                              154                                                                              1120                                                                              3660  1.0   4.5 × 10.sup.6                                                                 -10.3 2.1   -4.4  -5.2                              1555                                                                             1120                                                                              3780  1.1   4.8 × 10.sup.6                                                                 -10.6 2.1   -5.6  -6.4                              156                                                                              1120                                                                              3750  1.1   6.0 × 10.sup.6                                                                  -8.6 1.3   -4.6  -4.8                              157                                                                              1120                                                                              3660  1.1   4.0 × 10.sup.6                                                                  -9.8 3.3   -5.4  -7.1                              158                                                                              1130                                                                              3850  1.2   4.4 × 10.sup.6                                                                  -9.3 3.5   -4.7  -7.2                              159                                                                              1250                                                                              Not coherently bonded on firing                                        160                                                                              1170                                                                              4120  1.4   2.1 × 10.sup.6                                                                  -9.7 2.4   -3.9  -4.1                              161                                                                              1140                                                                              4140  0.9   2.5 × 10.sup.6                                                                  -7.8 4.6   -3.6  -5.6                              162                                                                              1120                                                                              3690  1.0   3.0 × 10.sup.6                                                                  -7.6 0.1   -4.0  -7.1                              163                                                                              1070                                                                              3420  0.2   2.3 × 10.sup.6                                                                 -11.4 -1.9  -5.4  -9.3                              164                                                                              1050                                                                              2870  1.3   1.6 × 10.sup.6                                                                 -14.2 -6.2  -8.0  -10.1                             165                                                                              1250                                                                              Not coherently bonded on firing                                        166                                                                              1170                                                                              4230  1.3   4.8 × 10.sup.6                                                                   2.1 3.6   -5.8  -1.2                              167                                                                              1140                                                                              4020  0.9   5.0 × 10.sup.6                                                                 -10.6 6.8   -6.5   0.1                              168                                                                              1110                                                                              3740  0.9   5.5 × 10.sup.6                                                                 -10.1 2.8   -6.7  -3.7                              169                                                                              1070                                                                              3340  1.1   2.8 × 10.sup.6                                                                 -11.6 -0.7  -7.9  -5.9                              170                                                                              1040                                                                              2940  1.4   2.6 × 10.sup.6                                                                 -16.2 -4.8  -9.1  -6.3                              __________________________________________________________________________

It will be noted from Table 4 that the specific dielectric constants ofthe Test No. 1 capacitors, for instance, averaged 3920, their dielectriclosses 1.1 percent, their resistivities 5.6×10⁶ megohm-centimeters, andtheir percent variations of capacitances from those at 25 degrees C. tothose at -55 degrees and +125 degrees C., -10.2 and +3.0 percent, andfrom those at 20 degrees C. to those at -25 degrees and +85 degrees C.,-5.3 and -6.0 percent, respectively.

Before proceeding further with the examination of Table 4, we willdetermine the criteria of acceptability for the four electricalproperties in question of the capacitors as follows:

Specific dielectric constant, at least 3000.

Dielectric loss, not more than 2.5 percent.

Resistivity, at least 1×10⁶ megohm-centimeters.

Temperature dependence of capacitance, within plus and minus 15 percentat -55 degrees and +125 degrees C., and within plus and minus 10 percentat -25 degrees and +85 degrees C.

A reconsideration of Table 4 in light of the above established criteriaof favorable capacitor characteristics will reveal that the capacitorsof Tests Nos. 11-16, 42, 47, 48, 53, 59, 62, 65, 68, 71, 74, 77, 78, 82,83, 87, 88, 98, 104-106, 112, 113, 117, 118, 122, 127, 139, 150-152,159, 164, 165 and 170 do not meet these criteria. Accordingly, thecorresponding ceramic compositions of Tables 1, 2 and 3 fall outside thescope of our invention. All the other test capacitors come up to thesecriteria even though they were sintered at temperatures of less than1200 degrees C. in a reductive atmosphere.

Although Table 4 gives the percent variations of capacitances only at-55 degrees, +125 degrees, -25 degrees and +85 degrees C., we actuallymeasured the capacitances at additional temperatures of 0 degrees, +20degrees, +25 degrees, +40 degrees, +60 degrees and +105 degrees C. Thecapacitance variations of all the test capacitors in accordance with ourinvention were within plus and minus 10 percent in the temperature rangeof -25 degrees to +85 degrees C. and within plus and minus 15 percent inthe temperature range of -55 degrees to +125 degrees C.

Now, let us study the ceramic compositions of Tables 1, 2 and 3, and thecorresponding capacitor characteristics of Table 4 in more detail.

As for the major ingredient, (1-α){(Ba_(k-x-z) M_(x) L_(z))O_(k)(Ti_(1-y) R_(y))O₂₋(y/2) }+αCaZrO₃, we tested various values for α, k,x, z and y in order to determine desirable ranges of such values. Firstof all, the value of the sum (x+z) was set at zero in Test No. 88. Inthe resulting capacitors the capacitance variation at -25 degrees C. wasoutside the desired range of plus and minas 10 percent, and thecapacitance variation at -55 degrees C. was outside the desired range ofplus and minus 15 percent. However, all the desired electricalcharacteristics were obtained when the value of the sum (x+z) was set at0.01 as in Tests Nos. 89-92. Thus we set the lowest possible value ofthe sum (x+z) at 0.01.

The tests Nos. 98, 104, 105 and 112 compositions had the value of thesum (x+z) set at 0.12. The capacitance variation of the resultingcapacitors at +85 or -25 or -55 degrees C. fell outside the desiredrange respectively. All the desired electrical characteristics wereobtained when the value of the sum (x+z) was set at 0.1 as in Tests Nos.102, 107, 108 and 111. The highest possible value of the sum (x+z) istherefore 0.1.

However, when the value of z was set at 0.06 as in the Test No. 106, allthe desired electrical characteristics were not obtained even though thevalue of the sum (x+z) was 0.06. All the desired electricalcharacteristics were obtained when the value of z was set at 0.05 as inTest No. 102. The highest possible value of z must therefore be 0.05.The possible values of x is the difference between (x+z) and z.

The capital M in the formula of the major ingredient represents eitheror both of Mg and Zn as aforesaid. The Tests indicate that the use ofeither or both of Mg and Zn does not substantially affect thecharacteristics of the resulting capacitors, and that the value of X canbe in the range of 0.00 to 0.1 in either case. The Tests also prove thateither or both of Ca and Sr may be employed as L without substantiallyaffecting the characteristics of the resulting capacitors, and that thevalue of z can be in the renge of 0.00 to 0.05 in either case.

The Tests Nos. 59, 62, 65, 68, 71, 74, 77, 127 and 139, compositions hadthe value of y set at 0.06. The dielectr bodies formulated accordinglywere not coherently bonded on firing. All the desired electricalcharacteristics were obtained when the value of y was set at 0.04 as inTests Nos. 58, 61, 64, 67, 70, 73 and 76. The highest possible value ofy is therefor 0.04.

The capital R in the formula of the major ingredient represents at leastone rare earth element selected from Sc, Y, Gd, Dy, Ho, Er, Yb, Tb, Tmand Lu as aforesaid. The Tests indicate that the use of one or plural ofthe rare earth elements does not substantially affect thecharacteristics of the resulting capacitors, and that the value of y canbe in the range zero to 0.04.

The addition of the rare earth elements to the major ingredient improvesthe temperature dependence of capacitance. The rare earth elements serveto make the capacitors that the capacitance variation is from -15percent to +15 percent in a temperature range of -55 degrees to +125degrees C., and form -10 percent to +10 percent in a temperature rangeof -25 degrees to +85 degrees C. Also, the rare earth elements serve tomake the dielectric bodies with a high resistivity. Furthermore, therare earth elements serve to make the ceramic bodies having highercoherency.

The value of α in the formula of the major ingredient was set at zero inTests Nos. 78 and 83. The capacitance variations of the resultingcapacitors fell outside the desired range of plus and minus 10 percentat -25 degrees C. and the desired range of plus and minus 15 percent at-55 degrees C. All the desired characteristics were met when the valueof α was set at 0.005 as in Tests Nos. 79 and 84. The lowest possiblevalue of α is therefore 0.005.

The value 0.05 chosen for α in Tests 82 and 87 was too high bacause thecapacitance variations of the resulting capacitors at 85 degrees C. felloutside the desired range of plus and minus 10 percent. All the desiredcharacteristics were achived when the value of α was set at 0.04 as inTests Nos. 81 and 86. The highest possible value of α is therefor 0.04.

When the value of K was set at 0.98 as in Tests Nos. 113 and 118, theresistivities of the resulting capacitors were less than 1×10⁶megohm-centimeters. The capacitor characteristics were all satisfactorywhen the value of K was set at 1.00 at in Tests Nos. 114 and 119. Thelowest possible value of K is therefore 1.00.

When the value of K was set at 1.07 as in Tests Nos. 117 and 122, theresulting dielectric bodies were not coherently bonded on firing.Coherently bonded ceramic bodies were obtained, and the capacitorcharacteristics were all satisfactory, when the value of K was set at1.05 as in Tests Nos. 117 and 122. The upper limit of the possiblevalues of K is therefore 1.05.

The ceramic compositions of Tests Nos. 42 and 48 contained no theadditive ingredient specified by our invention. The dielectric bodiesformulated accordingly were not coherently bonded on firing at atemperature as high as 1250 degrees C. For comparison the ceramiccompositions of Tests Nos. 43 and 49 contained 0.2 part by weight of theadditive ingredient with respect to 100 parts by weight of the majoringredient. Even though the firing temperatures for these testcapacitors were as low as 1180 and 1190 degrees C., they possessed thedesired electrical characteristics. We set, therefore, the lower limitof the possible proportions of the additive ingredient at 0.2 part byweight with respect to 100 parts by weight of the major ingredient.

The tests Nos. 47 and 53 ceramic compositions contained 7 parts byweight of the additive ingredient with respect to 100 parts by weight ofthe major ingredient. The specific dielectric constants of the resultingcapacitors were less than the above established criterion of 3000. Also,their capacitance variations were outside the range of plus and minus 15percent at -55 degrees C. However, when the proportion of the additiveingredient was reduced to five parts by weight as in Tests Nos. 46 and52 the resulting capacitors had all the desired electricalcharacteristics. Accordingly, the upper limit of the possibleproportions of the additive ingredient is set at five parts by weightwith respect to 100 parts by weight of the major ingredient.

We have ascertained from the results of the Tests Nos. 1-16 that theacceptable range of the relative proportions of Li₂ O, SiO₂ and MO, theadditive ingredient of the ceramic compositions in accordance with ourinvention, can be definitely stated in reference to the ternary diagramof FIG. 2. The point A in the ternary diagram indicates the Test No. 1additive composition of one mole percent Li₂ O, 80 mole percent SiO₂,and 19 mole percent MO. The point B indicates the Test No. 2 additivecomposition of one mole percent Li₂ O, 39 mole percent SiO₂, and 60 molepercent MO. The point C indicates the Test No. 3 additive composition of30 mole percent Li₂ O, 30 mole percent SiO₂, and 40 mole percent MO. Thepoint D indicates the Test No. 4 additive composition of 50 mole percentLi₂ O, 50 mole percent SiO₂, and 0 mole percent MO. The point Eindecates the Test No. 5 additive composition of 20 mole percent Li₂ O,80 mole percent SiO₂, and 0 mole percent MO.

The relative proportions of the additives Li₂ O, SiO₂, and MO of theceramic compositions in accordance with our invention are within theregion bounded by the lines sequentially connecting the above definedpoints A, B, C, D and E in the ternary diagram of FIG. 2.

Tables 1, 2, 3 and 4 prove that the additive compositions within theabove defined region makes possible the provision of capacitors of thedesired characteristics. The additive compositions of Tests Nos. 11-16all fall outside that region, and the corresponding dielectric bodieswere not coherently bonded on firing at a temperature of as high as 1250degrees C. The above specified acceptable range of the relativeproportions of the additives holds true regardless of whether only oneof BaO, MgO, ZnO, SrO and CaO is employed as MO, as in Tests Nos. 17-21,or two or more or all of them are employed as in the other Tests.

Also, we have ascertained from the results of the Tests Nos. 140-170that the acceptable range of the relative proportions of B₂ O₃, SiO₂ andMO, the additive ingredient of the ceramic compositions in accordancewith our invention, can be definitely stated in reference to the ternarydiagram of FIG. 3. The point A in the ternary diagram indicates the TestNo. 140 additive composition of one mole percent B₂ O₃, 80 mole percentSiO₂, and 19 mole percent MO. The point B indicates the Test No. 141additive composition of one mole percent B₂ O₃, 39 mole percent SiO₂,and 60 mole percent MO. The point C indicates the Test No. 142 additivecomposition of 30 mole percent B₂ O₃, 0 mole percent SiO₂, and 70 molepercent MO. The point D indicates the Test No. 143 additive compositionof 90 mole percent B₂ O₃, 0 mole percent SiO₂, and 10 mole percent MO.The point E indicates the Test No. 144 additive composition of 90 molepercent B₂ O₃, 10 mole percent SiO₂, and 0 mole percent MO. The point Findicates the Test No. 145 additive composition of 20 mole percent B₂O₃, 80 mole percent SiO₂, and 0 mole percent MO.

The relative proportions of the additives B₂ O₃, SiO₂ and MO of theceramic compositions in accordance with our invention are within theregion bounded by the lines sequentially connecting the above definedpoints A, B, C, D, E and F in the ternary diagram of FIG. 3.

Tables 1, 2, 3 and 4 prove that the additive compositions within theabove defined region makes possible the provision of capacitors of thedesired characteristics. The additive compositions of Tests Nos. 150-152all fall outside that region, and the corresponding dielectric bodieswere not coherently bonded on firing at a temperature of as high as 1250degrees C. The above specified acceptable range of the relativeproportions of the second additives holds true regardless of whetheronly one of BaO, MgO, ZnO, SrO and CaO is employed as MO, as in TestsNos. 153-157, or two or more or all of them are employed as in the otherTests.

Although we have disclosed our invention in terms of specific Examplesthereof, we understand that our invention is not to be limited by theexact details of such disclosure but admits of a variety ofmodifications or alterations within the usual knowledge of theceramists, chemists or electricians without departing from the scope ofthe invention. The following, then, is a brief list of such possiblemodifications or alterations:

1. The low temperature sinterable ceramic compositions of our inventionmay contain various additives other than those disclosed herein. Anexample is a mineralizer such as manganese dioxide. Used in a proportion(preferably from 0.05 to 0.1 percent by weight) not adversely affectingthe desired characteristics of the resulting capacitors, the mineralizerwill serve to improve the sinterability of the ceramic compositions.

2. The start materials of the ceramic compositions in accordance withour invention may be substances such as oxides or hydroxides other thanthose employed in the foregoing Examples.

3. The temperature of the oxidizing heat treatment need not neessarilybe 600 degrees C. but can be variously determined in a range (from 500degrees to 1000 degrees C. for the best results) not exceeding thetemperature of the preceding sintering in a nonoxidative atmosphere, theoxidizing temperature being dependent upon factors such as the paticularbase metal electrode material in use and the degree of oxidationrequired for each ceramic material to be produced.

4. The temperature of cosintering in a nonoxidative atmosphere may alsobe changed in consideration of the particular electrode material in use.We recommend a range of 1050 degrees to 1200 degrees C. if the electrodematerial is nickel, as we have ascertained by experiment that little orno flocculation of the nickel particles takes place in that temperaturerange.

5. The dielectric bodies formulated in accordance with our invention,with or without electrodes buried therein or otherwise attached thereto,may be sintered in a neutral, instead of reductive, atmosphere.

6. The principles of our invention may be applied to capacitors otherthan those of the monolithic, multilayered configuration disclosedherein.

What we claim is:
 1. A solid dielectric capacitor comprising adielectric ceramic body and at least two electrodes in contacttherewith, the dielectric ceramic body consisting essentially of:(a) 100parts by weight of a major ingredient expressed by the formula,

    (1-α){(Ba.sub.k-x-z M.sub.x L.sub.z)O.sub.k (Ti.sub.1-y R.sub.y)O.sub.2-(y/2) }+αCaZrO.sub.3

whereM is either or both of magnesium and zinc; L is either or both ofcalcium and strontium; R is at least one metal selected from scandium,yttrium, gadolinium, dysprosium, holmium, erbium, ytterbium, terbium,thulium and lutetium; α is a numeral in the range of 0.005 to 0.04, k isa numeral not less than 1.00 and not more than 1.05; x is a numeralgreater than 0 and less than 0.1; z is a numeral greater than 0 and notgreater than 0.05; the sum of x and z is a numeral not less than 0.01and not greater than 0.1; and y is a numeral greater than 0 and notgreater than 0.04; and (b) from 0.2 to 5.0 parts by weight of anadditive mixture of at least two members selected from the groupconsisting of boric oxide or lithium oxide, silicon oxide and at leastone metal oxide selected form the group consisting of barium oxide,strontium oxide, calcium oxide, magnesium oxide and zinc oxide.
 2. Thesolid dielectric capacitor of claim 1 wherein the additive mixture is anadditive mixture of lithium oxide, silicon dioxide and at least onemetal oxide selected from the group consisting of barium oxide,strontium oxide, calcium oxide, magnesium oxide and zinc oxide, therelative proportions of lithium oxide, silicon dioxide and at least oneselected metal oxide constituting the additive mixture being in thatregion of the ternary diagram of FIG. 2 attached hereto which is boundedby lines sequentially connecting:the point A where the additive mixtureconsists of one mole percent lithium oxide, 80 mole percent silicondioxide, and 19 mole percent metal oxide; the point B where the additivemixture consists of one mole percent lithium oxide, 39 mole percentsilicon dioxide, and 60 mole percent metal oxide; the point C where theadditive mixture consists of 30 mole percent lithium oxide, 30 molepercent silicon dioxide, and 40 mole percent metal oxide; the point Dwhere the additive mixture consists of 50 mole percent lithium oxide, 50mole percent silicon dioxide, and 0 mole percent metal oxide; and thepoint E where the additive mixture consists of 20 mole percent boricoxide, 80 mole percent silicon dioxide, and 0 mole percent metal oxide.3. The solid dielectric capacitor of claim 1 wherein the additivemixture is an additive mixture of boric oxide, silicon dioxide and atleast one metal oxide selected from the group consisting of bariumoxide, strontium oxide, calcium oxide, magnesium oxide and zinc oxide,the relative proportions of boric oxide, silicon dioxide and at leastone selected metal oxide constituting the additive mixture being in thatrigion of the ternary diagram of FIG. 3 attached hereto which is boundedby lines sequentially connecting:the point A where the additive mixtureconsists of one mole percent boric oxide, 80 mole percent silicondioxide, and 19 mole percent metal oxide; the point B where the additivemixture consists of one mole percent boric oxide, 39 mole percentsilicon dioxide, and 60 mole percent metal oxide; the point C where theadditive mixture consists of 30 mole percent boric oxide, 0 mole percentsilicon dioxide, and 70 mole percent metal oxide; the point D where theadditive mixture consists of 90 mole percent boric oxide, 0 mole percentsilicon dioxide, and 10 mole percent metal oxide; the point E where theadditive mixture consists of 90 mole percent boric oxide, 10 molepercent silicon dioxide, and 0 mole percent metal oxide; and the point Fwhere the additive mixture consists of 20 mole percent boric oxide, 80mole percent silicon dioxide, and 0 mole percent metal oxide.
 4. Thesolid dielectric capacitor of claims 1, 2 or 3 wherein the electrodesare buried in the dielectric ceramic body.
 5. The solid dielectriccapacitor of claims 1, 2 or 3 wherein the electrodes are of a basemetal.
 6. The solid dielectric capacitor of claim 5 wherein the basemetal is nickel.
 7. A process for the manufacture of a solid dielectriccapacitor which comprises:(a) providing in finely divided form a mixtureof: 100 parts by weight of a major ingredient expressed by the formula,

    (1-α){(Ba.sub.k-x-z M.sub.x L.sub.z)O.sub.k (Ti.sub.1-y R.sub.y)O.sub.2-(y/2) }+αCaZrO.sub.3

whereM is either or both of magnesium and zinc; L is either or both ofcalcium and strontium; R is at least one metal selected from scandium,yttrium, gadolinium, dysprosium, holmium, erbium, ytterbium, terbium,thulium and lutetium; α is a numeral in the range of 0.005 to 0.040; kis a numeral not less than 1.00 and not more than 1.05; x is a numeralgreater than 0 and less than 0.1; z is a numeral greater than 0 and notgreater than 0.05; the sum of x and z is a numeral not less than 0.01and not greater than 0.10; and y is a numeral greater than 0 and notgreater than 0.04; and from 0.2 to 5.0 parts by weight of an additivemixture of at least two members selected from the group consisting ofboric oxide or lithium oxide, silicon oxide and at least one metal oxideselected form the group consisting of barium oxide, strontium oxide,calcium oxide, magnesium oxide and zinc oxide; (b) molding the mixtureinto desired shape and size, the molding having at least two electrodeportions of an electroconductive material; (c) cosintering the moldingand the electrode portions to maturity in a nonoxidative atmosphere; and(d) heating the cosintered molding and electrode portions in anoxidative atmosphere.
 8. The process of claim 7 wherein the electrodeportions are formed on the molding by coating the same with anelectroconductive paste composed principally of a base metal.
 9. Theprocess of claim 8 wherein the base metal is nickel.
 10. The process ofclaim 7 wherein the molding and the electrode portions are cosintered ina temperature range of 1050 degrees to 1200 degrees C.
 11. The processof claim 7 wherein the cosintered molding and electrode portions areheated in a temperature range of 500 degrees to 1000 degrees C.